Three new ion exchange processes have recently been developed for purification of brine. The PDP (precipitator dust purification) process removes chloride contamination from byproduct sodium sulphate recovered from the electrostatic precipitator ofakraft pulp mill's recovery boiler. The BDS (brine de-sulphurization) process removes sulphate impurities from chlor-alkali cell brines, while a novel brine softening process is utilized to remove calcium and magnesium hardness from brine used for regeneration of brackish water softeners. The unique feature of these processes is that regeneration is accomplished with merely water, eliminating the handling and consumption of costly regenerant chemicals and their associated wastes. In addition, by utilizing a ion exchange technique called Recoflo, the height of the ion exchange resin bed can be reduced to only 30-60 cm. The basic equipment design, operation and application will be discussed and typical performance data will be presented.